Huge bomb found near Sri Lankan airport

On Tuesday the death toll from the attacks soared to 321, with more than five hundred injured

Police are still unclear as to who was behind the attacks, or the motivation for them

Twenty four people have now been arrested

COLOMBO, Sri Lanka - Twenty four people have been arrested in connection with the wave of terrorist attacks that swept across the island nation of Sri Lanka on Easter Sunday.

Police are still unclear as to who was behind the attacks, or the motivation for them.

On Tuesday the death toll from the attacks soared to 321, with more than five hundred injured.

The series of bombings shocked Sri Lankans as they understood their era of violence had long passeds, with the ending of the civil war a decade ago in 2009.

In a surprise development, Sri Lanka's Prime Minister Ranil Wickremesinghe has confirmed security officials were "aware of information" that attacks were planned, but had not acted on the intelligence.

In another development, trhe Sri Lankan Air Force revealed it had found a a huge bomb near the international airport just north of the capital.

"A PVC pipe which was six feet [1.8m] in length containing explosives in it was discovered," spokesman Gihan Seneviratne told local media.

(This story was updated Tuesday 23 April 2019 with the latest death toll).